1. Field of the Invention
The present invention relates to a magnetic tape cartridge where a single reel with magnetic tape wound thereon is rotatably housed within a cartridge case.
2. Description of the Related Art
In magnetic tape cartridges, which are being used as storage media that are employed in external storage units for computers, etc., there is known a type where a single reel with magnetic tape wound thereon is rotatably housed within a cartridge case. This magnetic tape is employed to archive data for computers, etc. Since important information has been stored, the magnetic cartridge is constructed so that problems, such as tape jamming, etc., do not occur and that the magnetic tape is not pulled out of the cartridge case unexpectedly.
Also, the magnetic tape has a tape leader pin firmly attached to the leading end thereof. When this magnetic tape cartridge is loaded into a recording-reproducing unit, a pin catching member on the side of the recording-reproducing unit engages the tape leader pin and pulls out the magnetic tape from the cartridge case. On the other hand, when the magnetic tape cartridge is unloaded from the recording-reproducing unit, the magnetic tape is rewound on the reel and the tape leader pin is returned into the cartridge case by the pin catching member.
The cartridge case is formed by fastening upper and lower cases of synthetic resin together with a plurality of small screws. The leader pin, as disclosed in Japanese Unexamined Patent Publication No. 11 (1999)-306722, etc., is detachably held in a vertical direction between the upper and lower cases, near a tape leader opening provided in the cartridge case. Also, near the tape leader opening, there is provided a slide door, urged toward a closing position by a spring, for opening and closing the tape leader opening.
FIGS. 1A and 1B illustrate the vicinity of the tape leader opening in the conventional magnetic tape cartridge described in the aforementioned publication. The open state and closed state of the slide door are shown in FIGS. 1A and 1B, respectively. The essential part of the slide door is shown in FIG. 1C.
In a side wall of the cartridge case 4 with an upper case 2 and a lower case 3 integrally fastened, a tape leader opening 10 is formed between the upper and lower cases 2, 3 and near the corner. A slide door 11 for opening and closing the tape leader opening 10 is provided so that it is slidable in a direction parallel to a direction where the magnetic tape is inserted into a recording-reproducing unit (i.e., the right direction in FIGS. 1A and 1B and therefore the right direction is taken to be the front direction of the cartridge case 4).
A leader pin 5 is detachably held within the cartridge case 4, facing the tape leader opening 10. The leader pin 5 is constructed, for example, of a metal main body and a synthetic-resin clamp member 5e, as shown in FIG. 1. The main body consists of a core shaft portion 5a to which the leading end of the magnetic tape 6 is clamped; thin flange portions 5b, 5b formed at the upper and lower ends of the core shaft portion 5a; and thick flange portions 5d, 5d formed outside the flange portions 5b, 5b through thin shaft portions 5c, 5c. The clamp member 5e has a C-cross section and is fitted elastically onto the outer periphery of the core shaft portion 5a. The thin shaft portions 5c, 5c are clamped by the pin holding member of the recording-reproducing unit when the magnetic tape cartridge is loaded into or unloaded from the recording-reproducing unit.
The slide door 11 is urged toward a closing position by a spring member compressed in the interior of the cartridge case and is held in the closing position shown in FIG. 1B. The slide door 11 is equipped with an engagement portion 12 that protrudes forward and outward from the front end (in the closing direction) of the door 11. If the magnetic tape cartridge is loaded into the recording-reproducing unit, the engagement portion 12 engages a member provided in the unit and the slide door 11 is opened. In the front wall of the cartridge case 4, a recess 8 is formed to house the engagement portion 12, with the front surface of the engagement portion 12 exposed through the front wall surface of the cartridge case 4.
In the magnetic tape cartridge constructed as described above, the front surfaces 11a, 11b, on the top side and bottom side of the engagement portion 12, of the slide door 11 abut the back surfaces 4a, 4b of the front wall of the cartridge case, whereby the slide door 11 is held in the closing position.
However, the front wall of the cartridge case 4 with the back surfaces 4a, 4b which are abutted by the front surfaces 11a, 11b of the slide door 11 is susceptible to shock, for example, when the magnetic tape cartridge falls. When subjected to such a shock, the front wall will be deformed and the positioning precision in the sliding direction of the slide door 11 at the closing position will be reduced.
With long-term use, the synthetic-resin rail portion and/or slide door 11 will wear and vertical play will develop in the slide door 11. Because of this, the positioning precision in the vertical direction of the slide door 11 at the closing position will be reduced.
Thus, if the positioning precision at the closing position of the slide door 11 is reduced, it will have detrimental effects on the opening operation for the slide door 11 based on the positional relationship between the engagement portion 12 of the slide door 11 and the engaging member of the recording-reproducing unit.
The upper and lower cases 2, 3 constituting the cartridge case 4 is usually fastened together by four small screws. However, in the case where the upper and lower cases 2, 3 are fastened together by small screws, the stem portion of the small screw requires a thickness of some magnitude or greater to have a screw groove therein. Furthermore, for these small screws, one of the upper and lower cases 2, 3 requires bosses having a transmission bore, while the other requires bosses having a screw bore. Therefore, space for these bosses has to be assured.
Near the holding portion for the leader pin 5, however, there is no space to provide bosses which are used for fastening small screws, because a tape running path is assured in order to avoid interference with the pin holding portion of the recording-reproducing unit. Because of this, the force fastening the upper and lower cases 2, 3 is weaker near the leader-pin holding portions than other parts.
Therefore, in the case where a strong shock is exerted on the cartridge case 4 because of a fall, etc., or in the case where a force of opening the upper and lower cases 2, 3 is exerted near the tape leader opening 10, there is a problem that the upper and lower cases 2, 3 in that portion will be moved away from each other and that the light, slender leader pin 5 will fall off the cartridge case 4.
To prevent the falling-off of the leader pin 5, the abutting surfaces of the upper and lower cases 2, 3 of the cartridge case 4 can be welded over the entire circumference. However, welding the abutting surfaces of the upper and lower cases 2, 3 is undesirable with regard to disassembly, because there is a need to disassemble the cartridge case 4 and take out the magnetic tape with important data along with the reel and then put them into a new cartridge case, in the event of an unforeseen accident, or after long-term use.
Furthermore, in the magnetic tape cartridge mentioned above, a memory element is provided to specify the contents of various data recorded on magnetic tape, tape type, etc., without reading them out. This memory element is equipped with a semiconductor chip and is constructed so that data recorded on magnetic tape is recorded on the memory element by a non-contact method such as electromagnetic induction, etc., and that contents recorded on the memory element are likewise read out by the non-contact method.
Such a memory element is provided in a part, within the cartridge case 4, which does not disturb rotation of the reel. In that case, it is necessary to mount the memory element at a position, desirable for a recording-reproducing unit into which the magnetic tape cartridge 4 is loaded, so that in the recording-reproducing unit, data can be written to or read from the memory element without difficulty. Furthermore, it is desirable that the mounting of the memory element in the cartridge case 4 be easily and efficiently performed concurrently with assembly of the cartridge case 4.
In view of the aforementioned circumstances, it is a first object of the present invention to provide a magnetic tape cartridge that is capable of preventing a reduction in the horizontal positioning precision, at a closing position, of the slide door even when subjected to a falling shock, etc.
A second object of the invention is to provide a magnetic tape cartridge that is capable of enhancing the vertical positioning precision, at the closing position, of the slide door.
A third object of the invention is to provide a magnetic tape cartridge which is capable of enhancing the fastening strength of the upper and lower cases near the leader-pin holding portion, while taking disassembly of the cartridge case into consideration.
A fourth object of the invention is to provide a magnetic tape cartridge which is capable of easily mounting a memory element in the cartridge case, at a position desirable for a magnetic recording-reproducing unit into which the magnetic tape cartridge is loaded, and in a predetermined posture.
To achieve the first object of the present invention mentioned above, there is provided a first magnetic tape cartridge comprising:
a cartridge case with a tape leader opening in side walls;
a single reel having magnetic tape wound thereon, and rotatably housed within the cartridge case; and
a slide door, which is urged toward a closing position by a spring and held in the closing position by abutting the cartridge case, for opening and closing the tape leader opening;
wherein the slide door has an abutting surface that abuts the cartridge case, the abutting surface being provided at a position spaced rearward from a front end of the slide door.
The cartridge case is provided with an abutting surface conforming to the abutting surface of the slide door. In this manner, the entry of dust is prevented.
According to the first magnetic tape cartridge of the present invention, the abutting surface of the slide door is provided at a position spaced rearward from the front end of the slide door. With this arrangement, the abutting surface of the cartridge case which abuts the abutting surface of the slide door can be provided at a position spaced from the corner portion of the cartridge case. Therefore, the first magnetic tape cartridge of the present invention is not easily affected by a falling shock, etc., and is capable of preventing a reduction in the positioning precision, at the closing position, of the slide door. In addition, since the abutting surface of the cartridge case is provided at a position spaced from the corner portion of the cartridge case, the corner portion can be reinforced by connecting the abutting surface and the corner portion through ribs, etc.
To achieve the second object of the present invention mentioned above, there is provided a second magnetic tape cartridge comprising:
a cartridge case with a tape leader opening in side walls;
a single reel having magnetic tape wound thereon, and rotatably housed within the cartridge case; and
a slide door, which is urged toward a closing position by a spring and held in the closing position by abutting the cartridge case, for opening and closing the tape leader opening;
wherein the cartridge further comprises means for positioning the slide door in the closing position and means for regulating a vertical position of the slide door.
In the second magnetic tape cartridge of the present invention, it is preferable that the means for positioning the slide door in the closing position also have the function of regulating the vertical position of the slide door. Positioning means for regulating both the horizontal direction and the vertical direction, at the closing position, of the slide door can be achieved by the abutting surfaces of the slide door and the cartridge case, inclined with respect to the direction where the slide door slides. The inclined surfaces may be tapered surfaces or curved surfaces.
According to the second magnetic tape cartridge of the present invention, the means for positioning the slide door in the closing position also has the function of regulating the vertical position of the slide door. Thus, the second magnetic tape cartridge of the present invention is capable of enhancing the vertical positioning precision, at the closing position, of the slide door. In addition, the positioning means for regulating both the horizontal direction and the vertical direction, at the closing position, of the slide door is obtained by the abutting surfaces inclined with respect to the direction where the slide door slides. Thus, the positioning means is achieved with an extremely simple construction.
To achieve the third object of the present invention mentioned above, there is provided a third magnetic tape cartridge comprising:
a cartridge case, formed by fastening upper and lower cases integrally, and having a tape leader opening in side walls of the upper and lower cases;
a single reel having magnetic tape wound thereon, and rotatably housed within the cartridge case; and
a slender leader pin firmly attached to a leading end of the magnetic tape and detachably held near the tape leader opening and between the upper and lower cases;
wherein a small-diameter pin for fastening the upper and lower cases is press-fitted near a holding portion of the cartridge case which holds the leader pin.
In the third magnetic tape cartridge of the present invention, the small-diameter pin may have a stem portion (of about 0.5 mm in outside diameter), a large-diameter head portion at one end of the stem portion, and a protrusion at the other end of the stem portion, the protrusion being provided to prevent the small-diameter pin from coming out.
In the case where the upper and lower cases are fastened together by small screws, as described above, the stem portion of the small screw requires a thickness of some magnitude or greater to have a screw groove therein. Furthermore, one of the upper and lower cases requires bosses having a transmission bore, while the other requires bosses having a screw bore. For these reasons, it is difficult to provide the bosses near the leader-pin holding portion. According to the third magnetic tape cartridge of the present invention, the upper and lower cases can be firmly fastened together by the small-diameter press-fit pin that requires no bosses. Therefore, the third magnetic tape cartridge of the present invention is capable of preventing the light and slender leader pin, held between the upper and lower cases, from falling off the cartridge case. In addition, in the case where there is a need to disassemble the cartridge case, the lower end portion of the small-diameter press-fit pin can be removed from the lower case, by removing the small screws and then applying force so that the upper and lower cases are opened, at the corner portions of the cartridge case opposite from the leader-pin holding portion. Thus, the cartridge case can be easily disassembled.
To achieve the fourth object of the present invention mentioned above, there is provided a fourth magnetic tape cartridge comprising:
a cartridge case, formed by fastening upper and lower cases integrally, and having a tape leader opening in side walls of the upper and lower cases;
a single reel having magnetic tape wound thereon, and rotatably housed within the cartridge case; and
a flat non-contact type memory element, where data is stored, housed within the cartridge case;
wherein the cartridge case is provided with an element mounting portion having an insertion slit open to a case surface, and after assembly of the cartridge case, the memory element is inserted through the insertion slit and held in the element mounting portion.
In the fourth magnetic tape cartridge of the present invention, the insertion slit may be formed in a side surface of the cartridge case, and the memory element may be inserted and held in the element mounting portion so that it forms an angle of approximately 45 degrees with the bottom surface of the cartridge case. Also, the insertion slit may be formed in the top surface or bottom surface of the cartridge case, and the memory element may be inserted and held in the element mounting portion so that it forms an angle of approximately 90 degrees with the bottom surface of the cartridge case. In addition, the memory element may have elastic portions at its side portions, and the memory element may be held in the element mounting portion by elastic deformation of the elastic portions produced when the memory element is inserted through the insertion slit. Furthermore, the memory element may be press-fitted in the element mounting portion through the insertion slit without providing the elastic portions.
The memory element is constructed such that data can be written to or read from one surface thereof. This surface is disposed in a predetermined posture at a position desirable for a magnetic recording-reproducing unit which uses this magnetic tape cartridge.
According to the fourth magnetic tape cartridge of the present invention, the flat non-contact type memory element is inserted through the insertion slit and held in the element mounting portion, after assembly of the cartridge case. Therefore, the mounting of the memory element in the cartridge case, at a position desirable for a magnetic recording-reproducing unit into which the magnetic tape cartridge is loaded, and in a predetermined posture, can be easily and efficiently performed along with assembly of the cartridge case.